#include <stdio.h>
#pragma pack(1) // 内存对齐
int main(void)
{
	struct date
	{
		int year, month, day;
	};
	struct student
	{
		char num[12], name[20];
		struct date  birthday;
		float score;
	} a;
	printf("The size of a is %llu bytes\n",sizeof(a));
}


